- How Quercetin Is Used to Help Allergies and High Blood Pressure
- The best quercetin supplement
- Quercetin: More Energy, Fewer Allergies
- HOW IT WORKS:
- Exercise stamina
- Pollen allergies and asthma
- Blood pressure
- HEADS UP:
- WHAT YOU SHOULD TAKE:
- Quercetin supplements lessen the effect of pollen allergies:
- Product examples
- Quercetin For Allergies | Herbal Remedies | Andrew Weil, M.D
- What Is Quercetin Used For?
- Quercetin Interactions And Warnings:
- When Buying Quercetin:
- Quercetin Dosages:
- Dr. Weil Says:
- Quercetin: Natural Support for Allergy & Inflammation Relief and More
- What is Quercetin? [Benefits & Uses]
- What is Quercetin?
- 9 Quercetin Benefits & Uses: Health Conditions Helped By Quercetin
- Quercetin Side Effects & Awareness Tips
- Learn More About Quercetin and the Ingredients that Help Allergies
- Feed Your Curiosity
What Is It?
When dealing with inflammatory conditions (such as eczema or allergies), there are several good reasons to consider products that combine bromelain, a natural anti-inflammatory derived from pineapples, and quercetin, a plant pigment (or flavonoid) prominent in apples and onions.
The main advantages of using combination bromelain/quercetin capsules are cost and convenience. Taking them together is also a smart move because they enhance each other’s anti-inflammatory actions. In addition, bromelain seems to increase the absorption of quercetin into the bloodstream.
With a combination product, the inflammation and itching of eczema may respond more rapidly than when either supplement is used alone. The same positive dynamic occurs when treating common allergy symptoms. Quercetin, a natural antihistamine, may be particularly helpful in relieving hay fever and other allergic reactions.
As a rule of thumb when calculating a combination dosage, try to get approximately the same number of milligrams of quercetin and bromelain. Finding a product that provides this balance may be a little tricky, so an approximation is just fine.
For more information on bromelain or quercetin, see the separate entries in the WholeHealth Chicago Reference Library.
Although no problems have ever been reported, theoretically you should use caution when combining bromelain with anticoagulants (blood thinners), such as coumadin or warfarin; as an extremely mild blood-thinner itself, bromelain increases the effect of a second blood-thinner. The best approach for anyone concerned about possible interactions with a specific drug or dietary supplement is to refer to the separate bromelain or quercetin entry in our WholeHealth Chicago Reference Library.
While bromelain and quercetin are generally considered safe, even at high doses, avoid taking this combination if you have an active gastric or duodenal ulcer. In addition, bromelain can actually cause an allergic reaction (red or itchy eyes, sneezing, running nose, throat irritation) in people who are sensitive to pineapples.
Check with your doctor before taking bromelain if you’re on prescription anti-inflammatory medication.
Allergies 100-200 mg bromelain and 400-500 mg quercetin 3 times a day between meals
Eczema 300 mg quercetin 3 times a day and 500 mg bromelain twice a day between meals (supplying 4,000 GDU or 6,000 MCU daily)
David Edelberg, M.D.
Many people with allergies clearly benefit from antihistamine medications. But nearly as many find the side effects distinctly unpleasant. This is where quercetin, especially when combined with the absorption-enhancing enzyme bromelain, may be helpful. Quercetin is apparently able to block both the manufacture and release of histamine, reducing inflammation in the airways and lungs.
HOW IT HELPS ALLERGIES
There are two good reasons to combine quercetin, a plant pigment that quells inflammation and has long been used for allergies and other inflammatory conditions, with the pineapple enzyme, bromelain. Not only is bromelain another natural anti-inflammatory, but it may actually enhance the absorption of quercetin into the bloodstream.
WHAT TO LOOK FOR
The quercetin-bromelain combination may be hard to find. Quercetin by itself is available in both capsule and powdered form. Bromelain comes in capsules. Any combination requires at least 300 mg of quercetin to produce an antihistamine effect.
Although allergic reactions are always possible, quercetin and bromelain are both extremely safe even in large quantities. For maximum absorption, you’re best off taking this particular combination on an empty stomach, or at least half an hour before or two hours after a meal.
For product recommendations and orders from the Natural Apothecary click here or call 773-296-6700, ext. 2001.
How Quercetin Is Used to Help Allergies and High Blood Pressure
Betsie Van Der Meer/Taxi/Getty Images
Quercetin is a chemical found naturally in a number of foods including apples, onions, teas, berries, and red wine. This flavonoid is also found in some herbs such as ginkgo biloba and St. John's wort.
Quercetin acts as an antioxidant, neutralizing free radicals—the chemical by-products that harm cell membranes and damage DNA. Available as a dietary supplement, quercetin also possesses antihistamine and anti-inflammatory properties.
In alternative medicine, quercetin is said to help with the following conditions:
- Cardiovascular disease
So far, results to support the benefits of quercetin are mixed—with some conditions examined only in test tubes or on animals. Here's how the research shakes out:
Quercetin is thought to prevent the release of histamine—an inflammatory chemical involved in allergic symptoms such as sneezing and itching—from certain immune cells. Although lab experiments suggest that quercetin may help fight allergic conditions allergic rhinitis, most have been performed in vitro or in animals. Researchers recommend further studies on humans to prove a correlation.
A 2016 review of randomized controlled trials found quercetin significantly reduced both systolic and diastolic blood pressure, particularly in diabetics who were given at least 500 milligrams per day. It's still unclear the precise dosage and duration to see the most benefits.
Quercetin may be no better than a placebo when it comes to enhancing athletic performance, according to a 2011 review of 11 previous studies. All studies showed a boost in exercise endurance via VO2 max—oxygen consumption during physical activity—when people ingested quercetin but the effect was minimal.
Another study found a more impressive link. A 2013 study analyzing 60 male students who've participated in athletics for at least three years saw improved lean body mass, total body water, basal metabolic rate, and total energy expenditure after taking quercetin.
Studies on cell cultures have shown that quercetin may help slow the growth of some types of cancer cells.
Some in vitro and animal-based research indicates that quercetin may protect against certain types of cancer, such as leukemia and lung cancer.
For example, a 2010 study looked at the relationship between quercetin intake and lung cancer risk in 38 non-tumor lung tissues and found an inverse correlation—the higher the intake of quercetin, the lower the risk.
However, since there is currently a lack of human studies on quercetin's cancer-fighting effects, it's too soon to tell whether quercetin might play a significant role in cancer prevention.
Quercetin is generally well-tolerated when used in appropriate amounts. Some have reported tingling in the arms and legs, as well as upset stomach and headaches when taking quercetin orally. Very high doses—greater than 1 gram per day—might cause kidney damage.
Supplements haven't been tested for safety and due to the fact that dietary supplements are largely unregulated, the content of some products may differ from what is specified on the product label.
Also keep in mind that the safety of supplements in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications—particularly antibiotics—has not been established.
Under the care of medical supervision, quercetin has been safely used in amounts up to 1,000 mg twice daily for 12 weeks. There is not enough evidence to know if it is safe for long-term use.
The appropriate dose for you may depend on factors including your age, gender, and medical history. Speak to your healthcare provider to get personalized advice if you choose to take this supplement.
Food sources of quercetin include teas, onions, apples, buckwheat, and pau d'arco. When taking quercetin in supplement form, it may be beneficial to choose a product that also contains papain and/or bromelain. These are plant-derived enzymes (fruit extracts) shown to increase the intestine's absorption of quercetin.
Due to the lack of supporting research, it's too soon to recommend quercetin for any health purpose. If you're considering using it, consult your primary care provider first. Self-treating a condition and avoiding or delaying standard care may have serious consequences.
Thanks for your feedback!
What are your concerns?
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Memorial Sloan Kettering Cancer Center. Quercetin. Updated December 6, 2016.
Mlcek J, Jurikova T, Skrovankova S, Sochor J. Quercetin and its anti-allergic immune response. Molecules. 2016;21(5):623. doi:10.3390/molecules21050623
Serban MC, Sahebkar A, Zanchetti A, et al. Effects of quercetin on blood pressure: a systematic review and meta-analysis of randomized controlled trials. J Am Heart Assoc. 2016;5(7). doi:10.1161/JAHA.115.002713
Kressler J, Millard-stafford M, Warren GL. Quercetin and endurance exercise capacity: a systematic review and meta-analysis. Med Sci Sports Exerc. 2011;43(12):2396-404. doi:10.1249/MSS.0b013e31822495a7
Askari G, Ghiasvand R, Paknahad Z, et al. The effects of quercetin supplementation on body composition, exercise performance and muscle damage indices in athletes. Int J Prev Med. 2013;4(1):21-6.
Lam TK, Rotunno M, Lubin JH, et al. Dietary quercetin, quercetin-gene interaction, metabolic gene expression in lung tissue and lung cancer risk. Carcinogenesis. 2010;31(4):634-42. doi:10.1093/carcin/bgp334
Penn State Hershey Milton S. Hershey Medical Center. Quercetin. Updated October 19, 2015.
Jin F, Nieman DC, Shanely RA, Knab AM, Austin MD, Sha W. The variable plasma quercetin response to 12-week quercetin supplementation in humans. Eur J Clin Nutr. 2010;64(7):692-7. doi:10.1038/ejcn.2010.91
- Zhang M, Swarts SG, Yin L, et al. Antioxidant properties of quercetin. Adv Exp Med Biol. 2011;701:283-9. doi:10.1007/978-1-4419-7756-4_38
The best quercetin supplement
Considerations when choosing quercetin supplements
Form: Most quercetin supplements come in capsule form, which are slick and generally easy to swallow. Kids, however, may do better with a gummy form that a select few manufacturers make. Powder forms of quercetin are also available and can be mixed into a beverage or food. Liquid forms are available in drops or sprays.
Dosage: The recommended dose of most quercetin capsules is two pills per day, or less with higher strength capsules. Powders and liquid forms are generally two scoops, two drops, or two sprays per day.
Potency: The strength of quercetin supplements can range between 500 milligrams and 1,200 milligrams per dose. The recommended daily dosage for children is lower, at 100 milligrams per day.
Additional ingredients: Some formulas include additional ingredients to enhance the antioxidant effects of quercetin. Bromelain, an enzyme derived from pineapples, is often added as is vitamin C, an antioxidant known for its immune-boosting effects.
Quercetin supplement prices
Quercetin supplements range in price from $13 to $40. A higher priced supplement may include added beneficial plant extracts or higher potency formulas.
Q. Can I take too much quercetin?
A. It's best to start with a low dose of 500 milligrams a day. Increased amounts, especially over 1,200 milligrams per day, can lead to upset stomach and diarrhea. Excessively high doses can lead to kidney problems.
Q. Who shouldn't take quercetin?
A. Don't take quercetin if you're pregnant or breastfeeding. People with high blood pressure may experience increased heart rate when taking quercetin supplements with bromelain. Always consult with your healthcare provider before starting a supplement regimen.
Quercetin supplements we recommend
Best of the best: Now Foods Quercetin With Bromelain
Our take: Trustworthy and quality quercetin supplement with added bromelain.
What we : This two-pack offers a generous supply of capsules. Each dose provides 800 milligrams of the flavonoid and 165 milligrams of bromelain. Vegetarian capsules.
What we dis: Don't take if you have an allergy to pineapples.
Best bang for your buck: Doctor's Best Quercetin Bromelain
Our take: An affordable option for a quercetin cap boosted with bromelain.
What we : Vegetarian capsules. Bioavailable form of quercetin. Gluten- and soy-free product. Low price for quality formula.
What we dis: Even with this low dose, can cause intestinal discomfort in some users.
Choice 3: Jarrow Formulas Quercetin
Our take: Pure, top-quality quercetin supplement at a steal.
What we : Doesn't contain bromelain, a plus for those sensitive to pineapples. Free of common allergens. Highly reputable brand. Popular with allergy sufferers. Vegetarian.
What we dis: Nothing.
Ana Sanchez is a writer for BestReviews. BestReviews is a product review company with a singular mission: to help simplify your purchasing decisions and save you time and money. BestReviews never accepts free products from manufacturers and purchases every product it reviews with its own funds.
BestReviews spends thousands of hours researching, analyzing and testing products to recommend the best picks for most consumers. BestReviews and its newspaper partners may earn a commission if you purchase a product through one of our links.
Distributed by Tribune Content Agency, LLC.
“,”author”:”Ana Sanchez”,”date_published”:”2019-08-22T12:39:00.000Z”,”lead_image_url”:”https://www.chicagotribune.com/resizer/ymxGteK-fie0DKDqhaDkoCwCCSc=/1200×0/top/arc-anglerfish-arc2-prod-tronc.s3.amazonaws.com/public/43IWO7M5MNBARAE2E32F3JFLWU.jpg”,”dek”:null,”next_page_url”:null,”url”:”https://www.chicagotribune.com/consumer-reviews/sns-bestreviews-health-the-best-quercetin-supplement-20190821-story.html”,”domain”:”www.chicagotribune.com”,”excerpt”:”Itâs allergy season, and if youâre looking for an alternative to allergy medicine, you may want to try a quercetin supplement. Quercetin is a âflavonoidâ found”,”word_count”:517,”direction”:”ltr”,”total_pages”:1,”rendered_pages”:1}
Quercetin: More Energy, Fewer Allergies
Quercetin (pronounced kwair-sih-tin) is an antioxidant flavonoid found in many different fruits and vegetables. Supplements have been found helpful in improving exercise stamina and prostatitis in people. Experimental evidence suggests that quercetin may be helpful in reducing blood pressure, pollen allergies, and possibly cancer risk.
Chemically, quercetin is closely related to rutin and quercitrin, two other flavonoids. Quercetin lacks a sugar molecule that is attached to these other flavonoids. When rutin and quercitrin are digested, intestinal bacteria remove the sugar molecule.
Thanks for watching!
HOW IT WORKS:
In addition to being an antioxidant, quercetin also has anti-inflammatory properties. It may alter the interaction between two key types of immune cells, Th1 and Th2.
Recent research on trained athletes and people just beginning a regimen of physical activity showed that supplemental quercetin can increase endurance. People taking 1,000 milligrams of quercetin daily had increased numbers of mitochondria in their muscle cells, which would help in energy production. In addition, quercetin may reduce the risk of flu after strenuous exercise.
In one study, J. Mark Davis, PhD, and his colleagues at the University of South Carolina, Columbia, tested 12 sedentary subjects' endurance on an exercise bicycle.
After taking quercetin supplements-500 milligrams twice daily for one week-the subjects' lung function and stamina improved.
A separate study, conducted at Appalachian State University in Boone, North Carolina, found that 1,000 milligrams of quercetin led to better treadmill workouts after only two weeks.
Thanks for watching!Thanks for watching!
Nonbacterial prostatitis causes severe pelvic pain and is difficult to treat, but quercetin may be of tremendous benefit.
Researchers at the Institute for Male Urology, in Los Angeles, gave men with prostatitis 1,000 milligrams of quercetin daily for a month. Two-thirds of the men had at least a 25 percent reduction in symptoms.
When the doctors added bromelain and papain supplements to enhance quercetin absorption, 82 percent of the patients got better.
Pollen allergies and asthma
Alternatively minded physicians have long suggested quercetin supplements to help ease pollen allergies. There's good reason for the recommendation. A Japanese study of 20 people with pollen allergies found that quercetin supplements reduced eye irritation and itching.
The subjects were given 200 milligrams of a proprietary form of quercetin for eight weeks. Meanwhile, an animal study found that quercetin significantly reduced asthmatic reactions.
Still other research has found that quercetin reduces the reactivity of mast cells, which release histamine during allergic reactions.
Some evidence suggests that quercetin supplements might help lower blood pressure. Researchers at the University of Utah found that people with mild hypertension improved after taking 730 milligrams of quercetin daily for 28 days. Quercetin had no effect on people with normal blood pressure.
The richest food sources of quercetin are capers, lovage (also known as sea parsley), buckwheat, and apples. It's also concentrated in honey and the outermost rings of red onions.
When shopping for quercetin, look for supplements in capsules. Some quercetin-containing sports drinks contain either too little quercetin or too much sugar.
WHAT YOU SHOULD TAKE:
To ease pollen allergies, start with 250 milligrams of quercetin daily. If it doesn't alleviate symptoms, slowly increase the daily amount to 1,000 milligrams. For prostatitis, take 1,000 to 2,000 milligrams daily. To increase exercise endurance, take 1,000 milligrams daily.
The doctor suggested quercetin supplements. Jennifer started taking 250 milligrams of quercetin with each meal and noticed an improvement in her allergies.
After reporting back to her doctor, he suggested that Jennifer add bromelain and papain, two digestive enzymes that help the body absorb quercetin.
The addition of these supplements led to a significant reduction of Jennifer's allergies.
Did you know?
Research indicates that quercetin may slow the growth of, or even induce the death of, cancer cells. A form of quercetin is now being used experimentally to treat some cancers.
Quercetin supplements lessen the effect of pollen allergies:
Jennifer suffered from pollen allergies and occasional asthma episodes throughout the year. Medications made her drowsy, so she saw a naturopathic physician to investigate natural remedies that might help.
Jarrow Formulas Quercetin 500 capsules provides 500 mg of the flavonoid in just one capsule.Twinlab Quercetin+C combines noncitrus vitamin C (1,400 mg) with 500 mg of quercetin in two capsules.Irwin Naturals Aller-Pure softgels help alleviate allergy symptoms and boost immunity with a mix of herbs and nutrients, including 300 mg of quercetin.
Reserveage Organics Ultimate Antioxidant blends the powerful antioxidant resveratrol from red grapes with 100 mg of quercetin, pomegranate, green tea, cocoa, and grape seed extract.
Quercetin For Allergies | Herbal Remedies | Andrew Weil, M.D
- Vitamins, Supplements & Herbs
Quercetin is a bioflavonoid found in a variety of fruits, vegetables, and grains. Good sources of quercetin include buckwheat, apples, onions, kale, tomatoes, broccoli, asparagus, berries, red wine, and tea. Quercetin can also be taken in supplement form.
Flavonoids give flowers and fruits their vibrant colors and provide many health benefits. They are natural antioxidants and anti-inflammatory agents, and may offer protection against cancer, heart disease, and other age-related diseases.
What Is Quercetin Used For?
In the lab Quercetin stabilizes mast cells that release histamine, the principal mediator of reactions to pollen and other allergies, making it a natural antihistamine. It is used to treat symptoms of hay fever (when taken regularly for at least six to eight weeks), such as runny nose, watery eyes, and itching, as well as other forms of allergy and hives.
Research shows querccetin may be effective in improving the quality of life in men diagnosed with prostate cancer and reducing pain associated with prostatitis (inflammation of the prostate).
The flavonoids found in quercetin appear to protect against LDL (“bad”) cholesterol and may help lower high blood pressure.
Proponents of quercetin claim it can help treat a variety of other ailments including atherosclerosis, coronary heart disease, diabetes, and rheumatoid arthritis. It may also act as a performance enhancer for athletes by increasing exercise endurance.
Scientists are looking into the possibility that flavonoids, those found in quercetin, may play an important role in cancer prevention.
Studies show people with diets high in fruits and vegetables tend to have a lower risk of cancer.
Flavonoids have been shown to inhibit various cancers including breast, colon, ovarian, prostate, and lung cancer. Preliminary findings point to potential antiviral activity as well.
It must be noted that there is insufficient reliable information to prove these claims and more studies are needed.
Quercetin Interactions And Warnings:
Headaches and tingling of extremities are side effects that have been reported when taking quercetin orally. Intravenous injection is associated with sweating, nausea, and vomiting.
High doses of quercetin (more than 1 g per day) may cause kidney damage.
People with kidney disease and women who are pregnant or breastfeeding should not take quercetin.
Talk to your doctor before taking quercetin if you are taking warfarin, aspirin, clopidogrel, corticosteroids, cyclosporine, digoxin, chemotherapy, or medications that affect liver function.
When Buying Quercetin:
Look for coated tablets, which are easiest to swallow. Avoid powdered quercetin.
For hay fever, take 400 mg twice a day between meals. For general health, you can take between 100 to 250 mg of quercetin three times a day.
Dr. Weil Says:
Although supportive research data are lacking, many of my patients who have suffered for years with seasonal allergies have found welcome relief from quercetin. Some have even prevented episodes by taking quercetin in the weeks preceding pollen season. Try it and see if your symptoms improve.
SOURCES:American Cancer Society – cancer.org/Treatment/TreatmentsandSideEffects/ComplementaryandAlternativeMedicine/
Natural Health, Natural Medicine: The Complete Guide to Wellness and Self-Care for Optimum Health. By Andrew Weil, MD
Natural Database – naturaldatabase.therapeuticresearch.com/nd/Search.aspx?cs=NONMP&s=ND&pt=100&id=294&fs=ND&searchid=37227192
University of Maryland Medical Center – umm.edu/altmed/articles/quercetin-000322.htm
Li Y, Yao J, Han C, et al. Quercetin, Inflammation and Immunity
Nutrients 2016;8,167; doi:10.3390/nu8030167.
Serban M-C, Sahebkar A, Zanchetti A, et al. Effects of quercetin on blood pressure: a systematic review and meta-analysis of randomized controlled trials. J Am Heart Assoc 2016;5: e002713.
Zhang M, Lin JM, Li XS, et al. Quercetin ameliorates LPS-induced inflammation in human peripheral blood mononuclear cells by inhibition of the TLR2-NF-κB pathway. Genet Molecul Res 2016;15:gmr.15028297
Reviewed by Russell Greenfield, M.D., August, 2016.
Quercetin: Natural Support for Allergy & Inflammation Relief and More
Studies find that the dietary flavonoid quercetin – a potent antioxidant able to promote proper antihistamine and anti-inflammatory responses – may support cardiovascular, metabolic and respiratory health, and shows promise in the field of cancer research.
Quercetin is found in foods apples, red onions, tea, red grapes, leafy-green vegetables and several kinds of berries. It’s the flavonoids that are responsible for the bright reds, yellows and oranges found in many of our plant foods. Of the more than 6,000 known flavonoids, quercetin is the one most often taken in supplement form.
Quercetin’s Role in the “French Paradox”
News stories have widely publicized the health benefits of drinking red wine.
Scientists initially began looking at red wine as a possible explanation for the “French Paradox” – the observation that the French have a relatively low mortality rate from heart disease even though they smoke and eat diets high in saturated fats.(1) Studying 18 developed countries, researchers found a strong link between low heart disease mortality and wine consumption.(2)
The news reports attributed much of the health benefits from red wine to the polyphenol resveratrol. While red wine does contain resveratrol, it contains even higher levels of flavonoids – notably Quercetin – which has made some less-publicized, but no less-impressive news of its own.
Quercetin has long been known for its antihistamine and anti-inflammatory supporting properties. More recently, research has revealed that it may also help to promote longevity and protect against cardiovascular disease, metabolic syndrome, obesity, and cancer.
Let’s take a look at some of the science supporting the effects of this powerful little flavonoid.
Quercetin’s Effects on Allergies and Asthma
Quercetin acts as a natural antihistamine by helping prevent the release of histamine from mast cells and basophils (the culprit in hay fever’s itchy, watery eyes, runny nose, and sneezing, for example). A number of animal studies have been done to evaluate results of quercetin supplementation vis a vis asthma and allergic reactions. Here are just three examples:
• A South Korean study found that pretreating asthmatic mice with quercetin supported a significant inhibition of asthmatic reactions.(3)
• In a Brazilian study, all of the mice pretreated with quercetin were protected from fatal anaphylactic shock when challenged with an allergen, compared with 100% mortality in the untreated group.(4)
• A 2008 study using guinea pigs compared quercetin supplementation with prescription asthma medications. Quercetin supported a greater reduction of airway resistance than was achieved with the drug albuterol and as much as with the medications cromolyn and dexamethasone.(5)
Anti-inflammatory Benefits of Quercetin
The medical profession now knows that inflammation plays a part in virtually every chronic disease as well as many acute conditions. Quercetin is a powerful antioxidant that has been shown to promote the reduction of inflammation throughout the body.
• A 2007 study demonstrated how quercetin supplementation helped inhibit the production of pro-inflammatory cytokines associated with the mast cell-mediated allergic inflammation involved in diseases rheumatoid arthritis, asthma and sinusitis. The researchers concluded, “Our study provides evidence that quercetin may [be] suitable for the treatment of mast cell-derived allergic inflammatory diseases.”(6)
• Serum C-reactive protein (CRP) is known to be a biomarker for chronic inflammation and a risk factor for a number of illnesses, including lupus and cardiovascular disease.
Scientists at Michigan State University studied 8,335 adults to find out which foods could help lower serum CRP. They discovered that those who ate the most foods high in flavonoids had the lowest serum CRP levels.
Of the flavonoids they studied, quercetin was at the top of the list for its ability to help the body protect against high serum CRP and thus protect against inflammation.(7)
Reducing the Risk of Cardiovascular Disease
Epidemiological studies have found that quercetin intake is associated with reduced risk of coronary heart disease and stroke.
• The oxidation of LDL has been recognized as playing an important role in the initiation and progression of atherosclerosis. In 2000, a study of 21 male subjects concluded that quercetin supplementaion can help the body inhibit LDL oxidation.(8)
• In 2007, University of Utah researchers conducted a randomized, double-blind, placebo-controlled, crossover study evaluating quercetin supplementation as a means of supporting lower blood pressure in hypertensive patients.
Nineteen people with prehypertension and 22 people with stage 1 hypertension were given 730 mg of quercetin or a placebo.
Although there was no change in blood pressure in the prehypertension group, there was a significant reduction in systolic, diastolic, and mean arterial pressure in the stage 1 hypertensive subjects who took quercetin.(9)
Quercetin’s Role in Metabolic Syndrome, Diabetes and Obesity
Current research is increasing the understanding of the role quercetin may play in helping to overcome obesity and managing metabolic syndrome – a group of risk factors that increase the risk for cardiovascular disease and type 2 diabetes.
• Spanish researchers undertook a study to analyze the effects of chronic administration of high doses of quercetin on metabolic syndrome abnormalities, including obesity, high cholesterol/ triglycerides, hypertension, and insulin resistance.
Obese rats were given a daily dose of quercetin – either 2 mg/kg or 10 mg/kg of body weight – for 10 weeks.
Both groups demonstrated improvements in cholesterol/triglyceride levels, hypertension and insulin resistance, but only those fed the higher dose produced anti-inflammatory effects and a reduction in body weight gain.(10)
• Several laboratory studies have demonstrated that quercetin may support the body’s ability to inhibit fat accumulation, surpress the growth of new fat cells, and trigger the programmed destruction of existing fat cells.
One of the ways it works is by helping to block the uptake of glucose from the blood.
(11-13) Interestingly, two of the studies discovered that adding resveratrol or resveratrol and genistein to the quercetin dramatically increased its ability to support reduced fat accumulation.(12, 14)
Promising Advances in Cancer Research
Scientists are interested in studying quercetin as a support for cancer prevention and even as a possible treatment component because of its ability to support the body’s ability to suppress cell proliferation and trigger programmed cell death.
• Experiments done in cell culture and animal studies have shown that quercetin can play a role in preventing or slowing tumor development in several different types of cancer, including breast, brain, pancreas, liver, and colon.(15-19)
• An early Phase I clinical trial of quercetin supplementation was conducted in the United Kingdom. It involved 51 participants who had a variety of different types of cancer.
The results showed a decrease in the activity of the enzymes needed for tumor growth and evidence of antitumor activity.
Additional clinical trials must be done before it can be determined whether quercetin might be a viable supportive option in treatment of cancer.(20)
Need-to-Know Facts About Quercetin
Quercetin with Bromelain: Bromelain is a protein-digesting enzyme, derived from pineapple stems, that is added to enhance the absorption of quercetin into the body. Bromelain is widely used in sports medicine to combat the discomfort and swelling of bruises, sprains, and muscle tears.
Dosage: Recommended adult dosages range from 300 mg to 1,000 mg a day, usually divided into two or three doses. At very high doses, there have been some reports of damage to the kidneys, so it’s best not to take more than 1 gram (1,000 mg) per day without talking with your doctor.
Contraindications:– Do not take quercetin with bromelain if you are allergic to pineapple.– May enhance effects of anticoagulants and increase risk of bleeding.– May interfere with absorption of the immune suppressant cyclosporine.– May cause corticosteroids to stay in the body longer.
– Consult a doctor before taking if you are pregnant, breastfeeding or have kidney disease.
Quercetin with its powerful “anti” properties – antioxidant, antihistamine, anti-inflammatory – may support cardiovascular, metabolic and respiratory health and shows promise in the field of cancer research.
1. Criqui MH, Ringel BL. Does diet or alcohol explain the French paradox? Lancet. 1994;344(8939-8940):1719-1723.
2. St Leger AS, et al. Factors associated with cardiac mortality in developed countries with particular reference to the consumption of wine. Lancet. 1979;1(8124):1017-1020.
3. Park HJ, et al. Quercetin regulates Th1/Th2 balance in a murine model of asthma. Int Immunopharmacol. 2008 Dec 2.
4. Cruz EA, et al. Immunomodulatory pretreatment with Kalanchoe pinnata extract and its quercitrin flavonoid effectively protects mice against fatal anaphylactic shock. Int Immunopharmacol. 2008 Dec 10;8(12):1616-21.
5. Moon H, et al. Quercetin inhalation inhibits the asthmatic responses by exposure to aerosolized-ovalbumin in conscious guinea-pigs. Arch Pharm Res. 2008 Jun;31(6):771-8.
6. Min YD, et al. Quercetin inhibits expression of inflammatory cytokines through attenuation of NF-kappaB and p38 MAPK in HMC-1 human mast cell line. Inflamm Res. 2007 May;56(5):210-5.
7. Chun OK, et al. Serum C-reactive protein concentrations are inversely associated with dietary flavonoid intake in U.S. adults. J Nutr. 2008 Apr;138(4):753-60.
8. Chopra M, et al. Nonalcoholic red wine extract and quercetin inhibit LDL oxidation without affecting plasma antioxidant vitamin and carotenoid concentrations. Clin Chem. 2000 Aug;46(8 Pt 1):1162-70.
9. Edwards RL, et al. Quercetin reduces blood pressure in hypertensive subjects. J Nutr. 2007 Nov;137(11):2405-11.
10. Rivera L, et al. Quercetin ameliorates metabolic syndrome and improves the inflammatory status in obese Zucker rats. Obesity (Silver Spring). 2008 Sep;16(9):2081-7.
11. Ahn J, et al. The anti-obesity effect of quercetin is mediated by the AMPK and MAPK signaling pathways. Biochem Biophys Res Commun. 2008 Sep 5;373(4):545-9.
12. Park HJ, et al. Combined effects of genistein, quercetin, and resveratrol in human and 3T3-L1 adipocytes. J Med Food. 2008 Dec;11(4):773-83.
13. Strobel P, et al. Myricetin, quercetin and catechin-gallate inhibit glucose uptake in isolated rat adipocytes. Biochem J. 2005 Mar 15;386(Pt 3):471-8.
14. Yang JY, la-Fera MA, Rayalam S, et al. Yang JY, la-Fera MA, Rayalam S, et al. Enhanced inhibition of adipogenesis and induction of apoptosis in 3T3-L1 adipocytes with combinations of resveratrol and quercetin. Life Sci. 2008 May 7;82(19-20):1032-9. Life Sci. 2008 May 7;82(19-20):1032-9.
15. Siegelin MD, et al. Quercetin promotes degradation of survivin and thereby enhances death-receptor mediated apoptosis in glioma cells. Neuro Oncol. 2008 Oct 29.
16. Choi EJ, et al. Antiproliferative effects of quercetin through cell cycle arrest and apoptosis in human breast cancer MDA-MB-453 cells. Arch Pharm Res. 2008 Oct;31(10):1281-5.
17. Vasquez-Garzon VR, et al. Inhibition of reactive oxygen species and pre-neoplastic lesions by quercetin through an antioxidant defense mechanism. Free Radic Res. 2008 Dec 29;1-10.
18. Tan S, et al. Quercetin is able to demethylate the p16INK4a gene promoter. Chemotherapy. 2009;55(1):6-10.
19. Warren CA, et al. Quercetin may suppress rat aberrant crypt foci formation by suppressing inflammatory mediators that influence proliferation and apoptosis. J Nutr. 2009 Jan;139(1):101-5.
20. Ferry DR, et al. Phase I clinical trial of the flavonoid quercetin: pharmacokinetics and evidence for in vivo tyrosine kinase inhibition. Clin Cancer Res. 1996 Apr;2(4):659-68.
* Karen Lee Richards is the Lead Expert specializing in Fibromyalgia and ME/CFS, for HealthCentral’s ChronicPainComnection (www.chronicpainconnection.com). Karen is co-founder of the National Fibromyalgia Association (NFA) and was Executive Editor of Fibromyalgia AWARE magazine for four years.
Note: This information has not been evaluated by the FDA. It is general and is not meant to prevent, diagnose, treat or cure any illness, condition or disease. It is very important that you make no change in your healthcare plan or health support regimen without researching and reviewing it in collaboration with your professional healthcare team.
What is Quercetin? [Benefits & Uses]
Need some relief from allergies?
It’s Quercetin histamine to the rescue!
If your diet is filled with Quercetin foods (fruits and vegetables), you are getting an abundance of Quercetin.
It’s a strange sounding word (it’s pronounced kwur-si-tin), but it’s a wonderful, naturally occurring compound that provides many health benefits in addition to allergy relief since Quercetin is a natural antihistamine, such as heart health, stronger immune system, pain relief, and even younger-looking skin.
In this blog article discussing Quercetin, LifeSeasons’ featured weekly ingredient, you’ll learn what Quercetin is, how this ingredient supports respiratory health, how Quercetin can lower histamine in the body, and Quercetin foods that you can eat daily, and lastly, you’ll learn about the benefits and uses of this compound.
What is Quercetin?
Quercetin is one of the best-known flavonoids (a diverse group of plant chemicals) and is found in many Quercetin foods such as fruits, vegetables, leaves, and grains.
1 Because it’s considered a plant pigment, Quercetin is prominently found in colored fruits and vegetables, especially those in red and orange pigmentation.
2 The strong antioxidant and anti-inflammatory effects of Quercetin play a noticeable role in our health.
As an antioxidant, Quercetin helps stop cells from being damaged by free radicals (waste produced by cells), thus protecting the immune system; as an anti-inflammatory, Quercetin inhibits certain chemical pathways from generating uncomfortable or painful inflammation.2
In your diet, Quercetin is most significantly found in onions, apples, citrus, kale, blueberries, and sweet potatoes, plus it can be found in green tea and red wine.2,3
9 Quercetin Benefits & Uses: Health Conditions Helped By Quercetin
With Quercetin being a powerful flavonoid, there is a wide range of health benefits, including its ability to reduce inflammation, eliminate pain, protect against cardiovascular diseases, act as an anti-cancer, boost the immune system, reduce histamines, and decrease irritation of the skin.2
Let’s take a closer look at the amazing benefits that can be ours, all thanks to Quercetin.
- Anti-Inflammatory – Inflammation is something that everyone experiences, and it happens when the body attempts to protect itself from harmful stimuli. However, chronic inflammation can lead to different conditions, which can include cancers, heart disease, and rheumatoid arthritis.4 Though further research is currently being done, Quercetin is thought to lower inflammation and inflammatory diseases IBS because of its antioxidant properties.5
- Pain Fighter – Because of the anti-inflammatory effects of Quercetin, painful conditions can be minimized. Autoimmune conditions, such as arthritis, and painful infections, such as prostate and respiratory infections, can benefit from Quercetin.5
- Natural Antihistamine – Histamines are chemicals in your body that your immune system makes, and they help your body to get rid of an allergen. In order to get rid of the allergen, the histamines cause you to sneeze or cough, have watery eyes or a runny nose, and feel itchy because it wants those allergens your body. The abnormal release of histamines can negatively impact your respiratory system leading to multiple health complications, such as redness, irritation, and swelling.8 Being loaded with antihistamines, Quercetin can help with these respiratory problems. It influences intracellular enzymes and reduces excessive histamine excretion.3
- Helps Asthma – Quercetin functions as a bronchodilator (a drug that opens the airways of the lungs) and reduces the amount of inflammatory or allergic reaction chemicals in the body.2 Therefore, Quercetin can reduce the severity of asthma attacks that react to those chemicals, and also reduce various forms of congestion that are unrelated to asthma.2,3
- Cardiovascular Health – Studies have shown that the consumption of flavonoids, specifically Quercetin, promotes overall cardiovascular health.3 First, it encourages blood flow. Secondly, researchers have observed that Quercetin’s antioxidant action protects against LDL cholesterol (the “bad” cholesterol) oxidation, and this may be beneficial because oxidation causes LDL cholesterol to stick to artery walls.3 Too much LDL cholesterol could cause atherosclerosis, heart attacks, and strokes.
- Balanced Blood Pressure – Along with supporting cardiovascular health, Quercetin naturally promotes balanced blood pressure. A randomized, double-blind placebo-controlled crossover study evaluated the effect of Quercetin supplementation and reported that the participants experienced a stabilization in systolic, diastolic and average arterial pressure.3
- Anti-Cancer – Quercetin, other flavonoids, seek out free radicals in the body and neutralize them before they can damage the bodily systems, and therefore, it becomes a potential in being an anti-cancer agent.6 Quercetin has been connected to a reduction in pancreatic, prostate, colorectal, and skin cancers, and although studies are ongoing, signs are pointing toward Quercetin being an important natural cancer-fighter.2,5
- Protects Against Stress – When your body is stressed, it produces cortisol. Cortisol is a hormone that produces that “fight or flight” response. Although this is normal, when your stress levels are high and ongoing, cortisol can damage muscle tissue, leading to protein breakdown in the body. Quercetin can fight these effects during times of extended stress as it suppresses the enzyme necessary for cortisol release.7
- Promotes Healthy Skin – According to dietitians, eating a Quercetin filled diet (lots of colorful veggies and fruits) can contribute to youthful looking skin.8 It nourishes your skin naturally and enhances your complexion as well. Being an antioxidant, Quercetin has an ability to fight factors that promote early aging.8
Quercetin Side Effects & Awareness Tips
Research agrees that Quercetin doesn’t have any inherent dangers; after all, it’s naturally found in foods-of-the-earth.
According to WebMD, there aren’t specific reported side effects from consuming a diet filled with Quercetin foods or taking a supplement by mouth short-term.
9 However, as with many things, if taken in high doses, there could be some risks, which include headaches, tingling of arms and legs, and in extreme cases, there could be kidney damage.9
If you’re pregnant or nursing, talk with your doctor first if you’re considering taking a Quercetin supplement and see about getting a Quercetin exam.
Learn More About Quercetin and the Ingredients that Help Allergies
Are allergies something you suffer with?
If so, here is how to reduce histamine in the body.
Taking Quercetin is a great option to help lower histamine levels quickly by combating those annoying allergy symptoms, all due to the powerful antihistamine effects it has.
If Quercetin histamine, in regards to ingredient knowledge, has piqued your interest for more information, here are some links where you can feed your curiosity:
We could all use a boost in helping us feel good, and Quercetin is a strong and natural booster of health. So go grab some tasty fruits and veggies and give your body a boost of health!
We’d love for you to share any insights and tips you have about Quercetin, how you use the supplement, and how it helps you with Allergies or Sinus support, if not more. Share with the LifeSeasons community and support our belief that knowledge is power and our community our life source.
Feed Your Curiosity
If you want to be the first to know about new posts from our blog, join our email list to receive updates with helpful tips for living a healthy life.